Antenna element



May 4, 1954 .1. w. COLLINS ETAL 2,677,765

ANTENNA ELEMENT Filed March 9, 1950 INVENTORS z/Ezmes WCo/fibs awe germ4G M 7 Patented May 4, 1954 UNITED STATES PATENT OFFICE ANTENNA ELEMENTApplication March 9, 1950, Serial No. 148,622

1 Claim. 1

This invention relates to antenna elements, particularly those elementsused in forming antenna structures for receiving short wavetransmissions in the television, frequency modulation and ultra-shortwave range, and the method of making such antenna elements as an articleof manufacture.

An object of the present invention is to provide a novel antenna elementwhich is an improvement over the extruded tubular elements now used informin most short wave or television receiver antenna structures.

Another object of the invention is to provide a novel, simple andeconomical method of producing the present improved antenna element.

A further object of the invention is to provide an antenna element whichis light in weight, highly resistant to bending stresses, and low incost, at the same time presentin no curtailment in efficiency as acollector of high frequency oscillations.

Still another object of the present invention is to provide an antennaelement which may be formed in a large variety of lengths and sizes andwhich may be used as masts and cross supports in antenna structures, asWell as receiving elements, and which are particularly adapted to beused with a suitable insulator such as described in our co-pendingapplication for Antenna for the Reception of High FrequencyOscillations, Serial No. 148,621, filed on even date herewith.

A further object of the present invention is to provide an antennaelement which when used in plural sets in an antenna structure resultsin a minimum of vibration and whistling, reducing breakage due tocrystallization and metal fatigue.

Still another object of the invention is to provide a tubular antennaelement which because of its core will not collect water, thuseliminating the bursting of the antenna element due to the freezing andexpansion of collected water and further eliminatin the need forflattening or sealing of the tube end as in the hollow, extruded tubularelement to prevent condensation therein.

A further object of the present invention is to provide an antennaelement so formed in a variety of ways such as a butting or overlappingsplit tube, laminations, coiled sprin wire or longitudinal folded ribs,that the element may expand radially due to temperature expansion or icepressure from capillary water without rupturing the casing, and returnto its original shape when such pressure is relieved.

Another object of the present invention is to provide an antenna elementthat is considerably more resilient than the extruded tubular elementusually used, and which may bend under heavy ice or wind loads andreturn to an original position without rupture of the casing.

A further object of the present invention is to provide an antennaelement that is formed with a metal casing and dielectric core, such aswood, plastic or the like, said core being treated to prevent moistureabsorption, and which element may permit the core to extend beyond themetal casing if desired to serve as an insulator for clamping theelements in a holding block of non-insulating material.

A final object of the invention is to provide an element which may becheaply fabricated by rolling in length or diameter or by dies in apower press and in which the core may be anchored or attached in variousWays to the metal casing,

With the above and other objects in View, as will become presentlyapparent, the invention consists in general of certain novel details ofconstruction and combinations of parts hereinafter fully described,illustrated in the accompanying drawings, and particularly claimed.

In the drawings, like characters of reference indicate like parts in theseveral views, and

Figure 1 is an elevation showing one method of fabricating the elements,as by rolling in length or diameter, and filling the outer tubing with acore and tightly joining the tube on the core;

Figure 2 is a sectiona1 perspective of one form of element;

Figure 3 is a view similar to Figure 2 of another form or modificationof the element;

Figure 3a is a section taken on the line 33 of Figure 3; and I Figures4a, 5, 6, 7 and 8 are views similar to Figures 2 and 3 of further formsor modifications of the element.

Referring to the drawings in detail, in Figure 1 is shown one method offabricating antenna elements of the present invention, in which a flatribbon or strip iii of dural or other conducting metal highly sensitiveto energization for sound and picture receiving of different wavelengths from different directions, is placed or fed from a strip, rollor reel onto a table i I and from thence, forward between coastinginterfitting forming rolls l2 and is placed one above the other androtatable about their axes It and it held in suitable bearing supports.Roll I2 is shown provided with one or more reduced portions iii intowhich the flanged periphery or annular conforming and overlappin edgeportions ll of roll I2 extends to partially bend the marginallongitudinal edge portions of narrow sheet or strip it up in offsetcurved fashion by a jog therein at and between the rolls l2 and I3, asshown at it. The strip Ill may be fed simultaneously with a rectilinearcore [9 thereon centrally of its Width, so as to be 5 partially bent upagainst the core. Core i9 is of uniform cross-section throughout itslength and suitable electrical insulating material, such as wood,plastic, or even metal or" solid, tubular or laminated form, or plasticWood to fill the completed outer tube of the element.

The strip and core are then fed forward from rolls l2 and :3 betweensimilarly mounted and journaled additional mating rolls 2e and iii oisimilar formation peripherally except that they may be differentlyproportioned in size and diameter and overlap to turn the edges of thestrip I6 up further in coiled form, as indicated at 22, so that thelongitudinal, marginal edges of the strip ill are brought toward eachother in closer relation on and about the core Eli but still in slightlyseparate relation to each other. After this, the strip and core are runbetween similarly mounted coacting circumferentially or peripherallyconcaved rolls 23 and 24, which turn the strip edges further to extendentirely around the core with their edges meetin and in contact to forma tubular shell about the core. The "clgee may be left in abutment asformed or joined in any suitable way, as by welding, soldering, orotherwise, along the joint formed by the ing edges of the formed tube itwhich is of un form cross-section throughout its length so t the core 59and the tube 25 will snugly interns each other throughout the lengththereof.

As shown in Figures 1 and 2, the tube along the marginal abutting edgesof the joint or seam 25 may be indented as at 2%? in one or more rows ofindentations to push the into e as at 28, and effectively anchor thetube to the core against separation, shifting movement or displacementrelative thereto. This may be accomplished in any suitable way, as bycoacting concaved rolls 29 and similarly journaled the other rolls andprovided with intermeshing circumferential peripheral teats, pins orprojections on one or both rolls iorci? the tube metal at such pointsinto forming depressions in the core with tight contact between the coreand shell or tube. The tube and core may be of suitable cross sectionalshape, and the tube wall of any thickness, and enveloping the core maybe deposited by electrolysis or plati if desired. The core may benatural wood, formed of plastic wood or any suitable pla or even metal,the latter being preferably, but not necessarily, a non-conductor ofelectric Cllrrent, and may be solid, tube or laminated to give desiredthickness and tensile strength, and of any diameter suitable for thepurpose.

In Figures 3 and 3a, the parts are similarly designated, but instead ofanchoring the tube on the core as in Figures 1 and Z, the rolls and 36may be formed peripherally to produce elon gated intermeshing linealindentations 33 which may or may not enter depressions 3?. or bedepressed into the core iii.

In Figure 4 the indentations are the same as employed in connection.with i and 2, but, in addition and instead of the edges of the stripshell or tube casing being brou ht into ab t ting relation and joined orotheri ise iistenel together or on the core, the edge margins arebrought into overlapping relation, as indicated at 3.3, and similarlyfastened, if desired, as previously explained.

In Figure 5, the construction method and product article of manufactureis the same as in Figures 1 and 2, except that the rolls are formed toproduce a tube 34. of rectangular and oblong cross-section with thesides bent at right angles relatively to snugly receive or lit the core35 of similar cross-section. Flanges 3S along the marginal edges arebrought together to form the seam 31 and anchored by similarindentations and depressions 21 and 28 as previously described, in thetubular shell and core, respectively.

In Figure 6, the tube 38 has the seam 39, and is fitted, formed orfilled with core 40. However, in this instance, the tube is shown formedwith longitudinal reinforcing ribs 4| which better allow for expansionof diameter and return to original shape. This tube may be anchored onthe core by indentations i2 entering depressions 43 formed thereby inthe core which has external ribs l-t longitudinally to enter theconcavities of the ribs 4| on the inside.

In Figure '7, the tubing 45 is formed of a coil wound on or filled withcore 48, may be fabricated by the conventional method of telescoping orby coiling wire or strap stock around the core compression therewith. Inthis form, the coils may form indentations or projections at the insideof the tube encircling the core and entering depressions orcircuinscribing annular or helical spiral grooves in the core peripheryformed by pressing the helical coils of the tube, or by filling the tubewith a plastic non-conductor, as heretofore described. It is also to beunderstood that in all the forms hereinbefore set forth, the tube may befilled completely with core to interiit at the indentations anddepressions formed by the indentations at the inside of the tubeentering the core at its pe riphery.

In Figure 8, a second coil or shell it? with or without core 46, thesame as in Figure 7, coiled or fitted over the coil forming a laminatedcovering or tube with plural layers, as may also be done with the otherforms of the invention not formed of coils, but layers of sheet metalplied one on the other. Also, this form may be used with or withoutsolid core 28, the inner coil serving as a hollow core.

The tube may be tempered as desired, and the core, especially of wood,can be coated or waxed to prevent moisture absorption, or the core maybe treated in any suitable or known way for this purpose. Also, anadhesive may be used to fasten the tube to the core, especially wherethe tube is too thin to firmly grasp and conform to the core tightly andstay tightly thereon.

In Figure do, the tube 2'6 and core it are the same as in Figures 1, 2,3 and 4, except that the joint may be a reinforcing and stiffening ribit, as in Figure 6, running longitudinally, and formed by a rolled lapor look joint 49 at the marginal edges of the metallic sheet or stripsealed at the inside at to hide and cover any raw or exposed edges ofthe strip.

In all forms, the element is of light weight, strong and rugged, anexcellent conductor, except the core which may be a non-conductor, andwhich may be extended from the tube and utilized as an insulator. Thelaminated or covered core construction results in superior strength overa simple tube, and may be used in proper sizes or diameters and wallthicknesses, as a mast or cross support for antenna as in our co-pendingapplication filed on even date herewith, or in stacking one antenna onanother supported by cross support bars on the mast to which they aresecured. Moreover, the core prevents the tube from crystallizing andbreaking due to vibration and metal fatigue in wind, and since it isimpossible for the tube to collect water on the inside to freeze andcrack the element, as a result of condensation, as is the case withtubing alone, no flattening of the tube ends or use of plugs therein isnecessary to seal the ends of the tube or give additional strength. Thetubes can be fabricated as described by rolling or turning in connectionwith Figure 1, or by rolling in length or diameter by rolls or discs, orprogressive dies, in a power press, and with the tube or casingcompletely or partially surrounding the core. The element may also beformed of a spring or group of laminated springs, one within and incontact with the other, and so wound as to be rigid enough to hold itsown weight and more. The advantage is that a heavy ice load which wouldbreak or destroy a hollow tube, would cause such spring elements to saginstead of breaking or permanently bending, and when the ice melts, theelement would return to its original straight and true rectilinear form.

While there is herein shown and described the preferred embodiment ofthe invention, it is nevertheless to be understood that minor changesmay be made therein without departing from the spirit and scope of theinvention as claimed.

What is claimed as new is:

As a new article of manufacture, an antenna {5 element for receivingshort wave transmissions in the television, frequency modulation andultra-short wave range, comprising an elongated electrical conductingtubular shell of uniform cross-section throughout its length and adielectric core therein and snugly and tightly interfitting within thetube throughout their lengths, said shell being anchored at closelyspaced points throughout its length to the core and being provided withlongitudinal reinforcing and stiffening formations, said reinforcing andstiffening formations being ribs located on the core and channels withinthe shell snugly interfitting thereon and thereby completely filling theshell.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 469,663 Greenfield Feb. 23, 1892 1,305,104 Hewitt May 2'7,1919 1,495,537 Stafford May 27, 1924 1,684,009 Brown Sept. 11, 19281,917,205 Horle July 4, 1933 1,981,090 Christman Nov. 20, 1934 2,160,258Berliner May 30, 1939 2,412,249 Brown Dec. 10, 1946 2,440,597 AtwoodApr. 27, 1948 2,542,884 Trebules et al. Feb. 20, 1951 FOREIGN PATENTSNumber Country Date 2,242 Great Britain May 18, 1911 of 1911 502,460Great Britain Mar. 17, 1939

